Archie Norman, the former Conservative MP, is preparing to step down as chairman of ITV, six years after he arrived at the troubled commercial broadcaster.

Sky News has learnt that Mr Norman has signalled to boardroom colleagues that he wants to leave the company later this year.

The search for his successor is being led by ITV’s senior independent director Andy Haste, who also runs Wonga, the payday lender.

City insiders suggested this weekend that the company may already have identified Mr Norman's replacement.

ITV’s board includes media heavyweights such as Sir Peter Bazalgette, the co-founder of Endemol, and Roger Faxon, a former EMI Music executive, although it is unclear whether an internal candidate is likely to take over as chairman.

Mr Norman’s exit is expected in a critical year for Britain’s broadcasting industry, with the BBC Charter Review due to take place and ministers contemplating privatising Channel 4.

The chairman of the London operation of Lazard, the investment bank, and Hobbycraft, the retailer, Mr Norman arrived at ITV in January 2010 to find a company facing significant financial and operational challenges.

It had spent lavish sums on failed purchases such as Friends Reunited, and was under intense pressure from leading shareholders.

Among Mr Norman’s first moves was to recruit Adam Crozier, the then boss of Royal Mail, as ITV's new chief executive.

Under their stewardship, ITV has soared in value, benefiting from a recovery in advertising spending, while it has invested heavily in content acquisition through the purchase of companies such as the Poldark producer Mammoth Screen and Talpa, producer of The Voice.

ITV’s shares closed on Friday at 259.4p, giving it a market value of almost £10.5bn.

The company’s biggest investor, Liberty Global, owns 9.9% of the shares - a stake it acquired from Sky, the owner of Sky News - but has so far explicitly ruled out a bid for ITV.

Recent tabloid speculation suggesting that NBC's owner, Comcast, had held talks with ITV about a takeover is said to have been inaccurate.

Mr Norman is just 61, and may yet take another big role at a major company.

Last year, he was close to being named as chairman of Tesco, the struggling supermarket chain, a move that had the backing of some City investors because of his successful stint in charge of Asda.

The Tesco role eventually went to John Allan, another well-regarded figure in the City.

The news that Mr Norman is preparing to step down is likely to mean that Mr Crozier will remain in place for some time.

Mr Crozier’s most recent strategic move was to announce the £100m purchase of the television assets of UTV Media, the owner of ITV's Northern Irish franchise.